Earlier on Monday, Rummenigge denied reports Bayern have already decided to sign James on a permanent basis, although he praised the Colombia star for his recent form.

Heynckes also admitted he does not know whether his two-year loan deal will be turned into a transfer, but he thinks James is transformed from the player who struggled under Carlo Ancelotti before the Italian's departure in October.

"Of course, I knew him before he came to Bayern," he said. "When I took over the team in the autumn, he wasn't physically fit. He is stronger physically now, he's a completely different player.

"He has integrated into the group and he feels very good. He'll definitely play at Bayern in the coming season but Bayern must decide what happens beyond that."